Sir Darnley Arthur Alexander, QC, CBE, GCON, SAN (28 January 1920 – 10 February 1989) was a Nigerian jurist and Chief Justice of Nigeria from 1975 to 1979.
He served as a crown counsel and legal draftsman in Jamaica and as Turks and Caicos Islands magistrate.
He was Legal Draftsman, Western Region, Nigeria from 1957 to 1969 and was acting Director of Public Prosecutions in 1958.
In 1960, he was appointed the Solicitor General and Permanent Secretary of the regional Ministry of Justice and in 1963, he was made Queen's Counsel.
As a judge, he was appointed by Dennis Osadebay to serve as the commissioner of enquiry into the Owegbe secret cult.